Water heating and steam generating unit



June 1l, 1946. P. B. WALLACE WATER HEATING AND STEAM GENERATING UNIT.Filed April 21, 19214 IN VEN TOR. PHILIP B. WXLLA as.'

I HTTDR/VE y vPressure steam.

Patented June 11, 1946 UNITED ST1-hres4 PATENT orties WATER HEATING ANDSTEAM GENERATIN G UNIT Philip B. WallacegSan Francisco, Calif.

Application April 21, 1944, Serial No. 532,041

6 Claims. (Cl. 122-181) -Mypresent invention relates to a heat ex-r lchanger device having heat induced convection circulation, andl moreparticularly relates to a boiler of simple and practical constructionfor heating water and/or generating steam.

j An object of the invention is to provide a simple and inexpensivewater heater or steam generating unit of novel construction which willbe particularly applicable to ynon-industrial uses, such as the heatingof water for homes, apartments, hotels and the like, or'for generatinglow vAnother object of the invention is to provide a 'novel boiler whichcan be constructed almost entirely of cylindrical members of differentlengths and diameters and in which the heat is applied in a nove1 andeconomical manner.

Another object of the invention is to provide an improved heat exchangeand baffle arrangement'for water heaters and the like in which the waterbeing heated will be subjected to a reheating circulation by convection.

Another `object of the invention is tok provide a sectionalized waterheating and l'steam generating'` unit 'which may-be easilyandfconvenientlyl disassembled for a periodic removal of scale vandother foreign particles to the end that a maximum eiliciency will bemaintained within the unit at all times.

In vthe construction of hot water heaters and e i.

steam generators of the size and type contemplated by my invention, ithas in the past been the custom to construct the various parts of castiron which may take many complicated shapes and which, because of thisfact, is expensive and l diflicult to clean and maintain. It is,therefore"y a further object of my inventionto provide a device whichcan be constructed entirelyy of wrought -metal 'pipe in a practical andinexpensive manner and which may be periodically disassembled for theremoval of scale in a simple and expeditious manner. n

Other objects Vand advantages of the invention will be in part evidentto those skilled in the art, and inpart pointed out hereinafter in thefollowing description taken in connection with the accompanying drawing,wherein there is shown by Way of illustration and not of limitation apreferred embodiment of the invention.

Invthe drawing;

Figure 1 is a sectional view taken along the longitudinal center line ofa multi-stage Water heating and steam generating unit constructed inaccordance with a preferred embodiment of the invention,

and 22 that projectv from the flue II.

Figure 2 is a fragmentary sectionalized view showing a modiiicationA ofthe device as illustrated in Figure 1 of the drawing, and

Figure 3 illustrates a further modified and sim'- pler form ofthe'invention for use with a heat conducting flue. A l

In Figure l of `the drawing I have shown a multiple stage 'water heatingand/0r steam generating unit constructedin accordancewith my inventionand employinga multiplicity of nested and concentrically arrangedlengths 'of pipe that arev assembled andvassociated with a v'single hotgas conducting flue in a novel manner. In this arrangement the hot gasesused for heating may 'be' taken from any suitable source, or I may em;

ploy a gas or oilburner I0 to provide the hot gases which, as hereshown, pass upwardly through a flue I I formed by a length of pipe thathas an outwardly extending llange I3 at a'point slightly below its upperenfd, anda second outwardly extending flange I Il nearits lower end.Secured to the underside of the ilange I3 and spaced from the 'flue I Ithere is a downwardly extendinglength of pipe I5 which carries aninwardly extending flange I 6 that vissecured to the -underside of theflange I4 by means of bolts Il. vThe outer'length of pipe I5 also has alluid in"- troducing inlet conduit lil'through which a fluid may beintroduced into the annular chamber thus formed around the flue II andbetween the said flue'and thepipe I 5. Positioned vwithin this annularchamber midway between the flue I I and the pipe "I5, and Awith itsupper end spaced from the flange I3 there is also an additionallength ofpipe I9` that has a plurality of notches or circulationpermittingapertures 20 in its lower end through which a fluid may passfrom one to the other side thereof. This bane forming 1ength of pipeA I9is held concentrically between the flue I IV and the pipe rI5 by meansof spaced bosses 2| At this point'it should be noted that'the gas or oilburner IG is' positioned within the flue II at a point where the fl-ametherefrom will be applied to the inside of the flue wall at la pointabove the notched apertures 20 formed in the bottom of the baffleforming pipe I 9 and, as a result, the Iluid in the chamber surroundingthe ue I I will be caused to circulate in a vertical direction aroundthe baille forming pipe I9.

The assembly thus far described may be considered to form the firststage of the heater or steam generator shown in Figure 1 of the drawing.As for the second stage of this embodiment of the invention, it will benoted that the outand it has a central aperture through which 'al lengthof pipe 25 extends. This pipe 26 is supported by an annular collar 21-that is welded'- thereupon which rests upon the hood 23, and at itslower end it is closed, as at 28, so that it'will form an elongatedpassageway through which the-- water or steam may flow in passing to thedis-l charge outlet. This pipe 26 also in turn supports" an internallydisposed length of pipe 29 that exv`.tendsdownwardly to apoint closely,adjacent the bottom or closed vend 28 of the :-pipe 26. f The internallydisposed V-length of pipe 2li-has a supporting. flange 30 that issecured by bolts or other 26. The pipe 26 is also here shownyas-provided With-a-discharge outlet A32 through which the -hot waterorA steam may be withdrawn from the unit.

-Afcapf 33 nis provided forclosing the upperlend vof the ,pipe 29,andAimmediatelybelow this' cap 33 there is. an -inletconduit-34 that;istconnected throughfa pipa-35 to' the interior offthe annularchamberformed between vthe ue :i Ira-nd ,the

pipe ,I I5 which, as will` new appear, -forms1 the outerwall or casingof theunit. ,The internally vdisposed'length of'. pipe 29` is here shownas hav- .ing a vseriesof spaced bosses 35 which vserve to Vmaintain itin ,central relation"with respect to the walls of the pipe-ZG-,fandat a;point approachmay .al'so,'if desired, be provided with-.a pluralityof.,l spaced apertures 31=that lie inea horizontal Yplane -andfprovidefor a'restricted recirculation ofthe waterbyconvectionias thewater. orsteam isfxbeing heated. In order to improve the-convectioncharacteristics provided ffor 4bythe aper.- tures13'l, it isYconteiinplatedthat the lower or closed endf28 of-thegpipezdwillbecoveredexL -ternally with Aa- -heat insulating means 38 that ywillprevent A-to some'extent; the direct applica,-

tion ofiheatto .the'outerwalls of `the rpipe'lZIV at a-point-where therelatively-cooler waterv or steam isdischargedfromthe Ylower endl of--thepipe 2 9. 1

Withwthis "arrangement it lwill be .seen' that whenftherflue -II i'sjheated, as described,above,v

and water is admitted through ,the .inletwconduit` I8 and withdrawnLfrom the Y,outlet conduit 32,v -thel heat-.within the' Vflue vI Lwill beconducted through the-.wallet said huerto-the water in the annularchamber -formedbetween the-flue; and the outer pipe tand, because -ofthe: baffle I9, this water will be caused to circulate by convectionaroundy the baffle in the ymannen-indicated bythe arrows applied tothisgure of the drawing. -Atthe same time, ifwater or steam isbeingwithdrawn from the-heater, the waterwill ow upwardly through thepipe-35 and the inlet conduit-34 to the-interior of theinternallyfdisposed length of pipe 29 and be discharged `at the lowerend thereofl and-into the lower endof the pipe 26. As the water'circulates through this pipe 26, the heat in theV flue II will be.conducted to a thinY film oflwater between-thepipes26 and 29.*a'nd,because of therestricted apertures 31, there willbe formed al 'secondconvection'circulation of the water as it is being heated. This meanstoa flangevyl atfthe upperend of thepipe g latter convection circulationwill be particularly active in the event that the water or steam is notbeing withdrawn from the generator at a rate corresponding to theheating thereof. In this operation the water in the outer annularchamber between the pipe I9 and the flue II will be preheated, and inthe inner space between the pipes 26 and A29- t will -be Asubjected to anal heating or Steam` generating operation.

From the above it will be seen that by the arrangement here described, Ihave provided a 1sirnple,.practical and inexpensive device that isvadapted to heat water and/or generate low pressure steam in anefficient and economical `manner. In the operation of water heaters andAsteam generators it is 'well known that scale and other sediment isprecipitated from the water during the heating operation and it is,therefore, also important, if full eciency is to be maintainedin aydevice of this character, toprovide .means-whereby thev` device1 vmaybey conveniently and effectively cleanedy of thi'sscale andother4mattenandy to` this end it will benoted that the flue II,.withy itsoutwardly..extendingwflangesv I3 and ,I4. isf-so constructed.that it maybe completely.. removed from the outerg-length ofjpipe I5 vby fanaxialdisplacement thereof. 1- AtY the A. same time, thebaiileiforming pipeI9l will alsol bey eX- posed insucha manner thatiit, too, Amaybe-readilyscrapedand cleaned of any scale orvother objectionable matter.The pipe 26,with its flange 21,-,is also arranged tobe lifted freeoflthefflue .II with thefvented hood 23 so that .itseicterior ksurfacemay be cleaned of soot ori.the-like,and.by 35 releasing theflange 30 of the internally disposed length ofrpipe.vl 29, `it will. bepossible .to withdraw this latter pipe sothat it-and thegpipe. 2IfcanAbe cleaned of-scalerand the like. In ordentopermit this; latteroperation, the pipe f 3.5 is shown.. as having a.union 39 forydisconnecting the inlet conduit 34' from the pipe135.v Asfalt auxiliary,the inlet lconduit 34 mayjhave-,a I.-coupling` 4i] from which anYadditional `concluitsM rextends,

' either furthe purpose Jof.. introducingfreshwater,

or withdrawinggpreheated wate1directly Yfrom the annular chamberbetweenthesfluefftl and tlleouterppipe.` I5. Because of-the` difference:in

the temperature of the flue Hand I'the outer pipe I5, it is possiblethat there -maynexist some Ldifferential inthe `rateof;expansifm-and/orcontractionrof these members land,= therefore, theouterfxpipe l-isfhere showna-a'srhaving asingle outwardlyextendingcorrugation 42 that is; adapted to compensate -for ,..anydifference in-rthe Ilexpansion or contraction which may occur.. be-

' tweenthe flue I'I and' pipe I5. Instead of-this corrugation 42, Vitvwill also be lpossibleV to compensateffor :any diiference inY'expansion or contractionbetween these-parteci the unitbyproviding acorrugated ilue I .,I. In this-latter-event, the corrugations of suchauewould-,have additional advantage of providingan increased heattransferring surface with which thewaterin theY outer annular chamberwould contact. e

Reference is now made to FigureZ of the-.drawing vwhich illustrates amodication of the -invention that, in other respects, issubstantially-identical to the arrangement described above. ,In

1 this arrangement the outer annular-chamber between the iiueY I l andthe outer-length of pipe I5 is here shown as sealed at its bottom kbythe provision of suitable packingv ringsAS.- that aredisposed betweenthe flanges I4 and I6 carried `respectively by these lengths of pipe.v.fAshere shown, the inner chamber is formed by a length vis ratherexposed to the iniiowing fresh cool air,

there will be no necessity `for the heat insulating covering previouslyreferred to as applied to the lower end of thevinner pipe 26. Because ofthis construction, it willalso be possible to provide the inner pipe 44with a-,blow-ofl valve 4l that will provide for a periodicdischarge ofany sediment which may collect yin the heater at this point. Like theabove described arrangement, it will be understood that since theinternally disposed length of pipe 46 terminates at a point below theburner 45, there will also be created a difference of temperatures inthe water at this point which will tend to set up the desirableconvection circulation, which is an important aspect of this invention.

In Figure 3 of the drawing there is shown a more simplified embodimentof the invention. This arrangement is particularly suited to the heatingof water in industrial plants where there exists a large amount ofexcess heat that is generally collected in a large ue which is connectedto a more distant stack. In this illustration I have shown only threesimilar units, designated by the numeral 48, that are arranged so as toextend vertically through a horizontally disposed flue 49. In thisarrangement the units 48 are projected through aligned openings in thetop and bottom walls of the ilue 49 and they are supported in thisposition by means of collars 50 that rest upon a top wall 5| of the ue49. At this point it will be noted that the lower ends of these units 48are allowed to project downwardly beyond the limits of a lower wall 52of the flue 49 where they will be exposed to the surrounding air whichwill be at a considerably lower temperature than the gases in the flue49. As shown in section at the left of this ligure of the drawing, eachof these units 48 is provided with a downwardly extending internallyarranged length of pipe 53 which terminates within that portion of theunits 48 extending beyond the lower wall 52 of the ue 49. Theseinternally arranged lengths of pipe 53 are also shown as provided withrestricted apertures 54 which permit a convection circulation within thewater contained in each of these units. At their upper ends theseinternally disposed pipes 53 are each shown as connected to a waterinlet manifold 55, and at the sides of the units 48 and above the Wall5I of the ilue 49 these units each have an outlet conduit 56 whichconnects with a hot water pipe or manifold 51. In this way when water isintroduced to the units 48 through the pipes 53 from the inlet manifold55, it will be subjected to heating by the hot gases within the flue 49and can then be withdrawn through the outlet conduits 55 and themanifold 51 to a point of use. The units 48 are each also here shown ashaving a removable plug 58 which will permit a removal of any sludge orscale that may accumulate at the bottoms of the units 48.

While I have, for the sake of clearness and in order to disclose theinvention so that the same can be readily understood, described andillustrated specic devices and arrangements, I desire to have itunderstood that the invention is not limited to the specific formdisclosed, but may be embodied in other ways that will suggestthemselves to persons'skilled in the art.i Itis believed that thisinvention is new andy it is desired yto claim it so that all suchchanges as come within the scope of the appended claims `are to beconsidered as part of this invention, 4,

.Having thus described my invention, what I Vclaim and desire to secureby Letters E'atent is: 1. In a fluid heating unit of the characterdescribed, the combinationof -a vertically disposed cylindrical pipehaving a closed bottom end, ymeans for applying heat to the outside lof,said pipe at apoint above its closed bottom end, and a uid directingconduit forming` a baille extending longitudinally into said rpipe andadapted to discharge a fluid to be heated into ther-interior of saidpipe below the pointof'heat application, whereby said iluid will besubjected to a violent convection circulation in said pipe as itisheated.

2. In a fluid heating unit of the character described, the combinationof a vertically disposed cylindrical pipe having a closed bottom, meansfor applying heat to the outer Wall of said pipe at a point above itsclosed bottom, and a fluid directing cylindrical baille extendinglongitudinally into said pipe and adapted to direct a iluid to be heatedagainst the inner wall of said pipe below the pointof heat application,whereby the fluid in said pipe will be caused to circulate by convectionas it is heated.

3. In a hot water heater of the character described, the combination ofa vertically extending flue, a closed relatively long cylindrical pipesuspended within said flue and having a lluid discharge outlet at itsupper end, a iluid introducing conduit extending through the top anddownwardly to a point closely adjacent the bottom of said pipe, heatinsulating means surrounding the lower end of said pipe at the pointwhere the iluid is discharged fromsaid fluid introducing conduit, saidfluid introducing conduit also having restricted apertures at its upperend communicating with the interior of said pipe, and means forsupplying hot gases to said ue above said heat insulating means, wherebythe luid within said pipe will be caused to recirculate by convection asitis heated.

4. In a hot water heater of the character described, the combinationwith a hot gas conducting llue of, a closed substantially cylindricalpipe suspended within said ue and having a fluid discharge outlet at itsupper end, a fluid introducing conduit extending within and throughoutsubstantially the entire length of said pipe and adapted to discharge afluid to be heated at the bottom thereof, said cylindrical pipe beinginsulated from the hot gases in said rlue at the point where the uid isdischarged from said fluid introducing conduit, and said fluidintroducing conduit having restricted recirculation apertures at itsupper end communicating with the interior of said cylindrical pipe,whereby the fluid within said pipe will be subjected to a partialrecirculation through said uid introducing conduit as it is beingheated.

5. In a water heating unit of the character described, the combinationof a vertically disposed hot gas conducting flue, a length of pipepositioned concentrically about said flue and supported thereupon at itstop and bottom by connecting ilanges to form an outer annular chamberabout said flue, a cylindrical baille positioned within, and spaced fromthe top of and extending substantially the entire. length of saidannular chamber and having notches through Vber, and affluidoutlet Stopof salid- Vouter fannular 'char'nb'er' Yand the top 0f' saiduidconducting conduit, a'fluid inlet 'for 'introducing a fluid3 into saidouter annular charnat'the top 'of said second length* of pipe, wherebyWater Within theunit will be simultan'eouslyv subjected to *a*preheating 'and 'recirculation' AWithin' said annular chambei and :tolal final e'circulatior and heating within said-second 1ength of pipe-bymenor, gsepagsa ling through said flue.

scribed, the ycombination of a' htgas enduoting flue, a verticallydisposed cylindrical'p'ipe extending into said ue and having 'its bottomend'.- in'- sulated from the hot :gases: in saidffluejwheieby the heatof said hot 'gases' Willbe'applied toi :the outer wall of lsaid pip'eatv a pointabove its Closed :10 bottomn'd, and- @fluid directingoylmdrieal conduit extending longitudinallyV throughfsaid heated intothe insulated bottom end'of 'saidr ver'- tically disposed pipe, wherebyan improvedfcon- `15 vection circulation Willbeiestablishedwithin 'saidpipe as said uid s heated. f Y y f f Y 1 l i" PHILIP B.'WALLACE.

